The invention relates to a rolling hoe (rotary hoe body) which is primarily a soil cultivating rotary machine being suitable in particular for loosening the soil, weed control, breaking up of clods, as well as for performing basic activities of soil cultivation.
In the course of the development of soil cultivating machines as a result of the interaction between technical level and agrotechnic knowledge, most different cultivating tools have been developed and spread in a wide circle. Magnitude of the profit to be gained in agricultural production determines the type of the commonly used tools based upon the known solutions under the given conditions.
In order to achieve satisfactory yields a properly compacted and sedimented seed-bed, with proper structure and free of weeds, has to be prepared.
Later on, weeds are to be uprooted in the spaces between the rows and the soil surface has to be aerated by loosening the soil in a depth of 2 to 6 cm. Stems of plants left in the soil are to be covered with earth. Soil ameliorating agents, including herbicides, are to be mixed with the soil. These operations require a plurality of machines, that means that several independent machines have to be set on the soil following one another. At the same time a further requirement lies in using soil cultivating machines which are able to perform simultaneous operations without deteriorating soil structure.
Operation of several machines requires a high expenditure on costs. Due to the repeated operative steps, machines require considerable hauling force.
Accordingly, specialized soil cultivating machines are required. The cultivating tools of these machines enable the performance of a plurality of cultivating operations in one single operative step.
From technical literature, patent specification and practice several solutions are known, which are more or less suitable for fulfilling the tasks set.
As such let us mention the U.S. Pat. Nos. 3,650,334, DE U.S. Pat. No. 1,457,716 and DE U.S. Pat. No. 1,457,714. These specifications deal with rotary hoes consisting of a central hub and of the radially extending teeth, which are bent backwards in relation to the natural sense of rotation in course of cultivation.
A common characteristic of the aforementioned solutions lies in that the axis of rotation of the hoes is running parallel with the soil surface.
Hoe-wheels form units, groups of hoes rotating on a common shaft. Axis of rotation of the hoe-groups is set at an angle deviating from 90.degree. in respect to the direction of advance.
A further common characteristic lies in that they are suitable only for loosing up the soil between the rows.
As a further deficiency it can be mentioned that the width of the soil zone which might be cultivated is relatively inconsiderable, the mass of the cultivator is large and manipulation is rather wearisome. Otherwise these machines do not meet functional requirements of soil cultivation.
Due to the considerable mass, teeth are frequently broken and the ability of penetration of the teeth into the soil is unsatisfactory. Weed control does not comply with the prescriptions of relating standards.
A solution more worthy of attention can be recognized from the U.S. Pat. No. 3,766,988.
The cross-section of the teeth is shaped so that these are able to penetrate into the soil vertically.
In order to avoid breaking of teeth, in accordance with the DE U.S. Pat. No. 2,528,928, the hoe-wheels are individually suspended.
Summing up what has been said about the rotary hoes, it can be stated that these are used within a most narrow range for performing special tasks of soil cultivation.
As such a task, consider breaking of the 1-2 cm thick surface soil layer preventing shooting up of seedlings, extermination of shooting up weeds, aeration of soil in between the rows, weed control in the space between two rows and building up ridges of small size on loose soil. In agricultural production all these applications do not surpass 1-2% of the total working time expended on soil cultivation. That means that proportion of activity of cultivating bodies with rotary hoes is presently inconsiderable.
Other cultivating tools are of different types and effectuation.
It is characteristic for operation, in so far as different loosening tools are used for loosening the soil, that ploughs and cultivating tools with discs cover plant stems left behind with earth, different cylinders are compacting the soil and ridges are filled up with filling hoe bodies. Weed control is realized by using cultivator hoes, furrows are broken up with cylinders serving for this purpose, stems have been left behind, and clods are comminuted with special cutting discs and cultivating means provided with discs, weeder and soil-ameliorating agents are mixed into the soil by means of tools provided with discs or cutting spades, etc.
In connection with said cultivating means it can be stated that beside the advantageous features, significant disadvantages appear. If these could be eliminated, considerable economic profit could be achieved.
When plough and soil cultivating means provided with discs turn the soil, moisture balance of the cultivated soil will be negatively influenced. Loosening means and cultivator hoes collect weeds and remnants of plant stems, twigs etc., so they often get clogged. Cultivator hoes serving for weed control have to be sharpened daily, or every second day, by manual forging or in any other way known in itself, as otherwise they do not penetrate into the soil.
With the exception of ploughs, the majority of cultivating means may be operated in the range of low soil moisture with advantageous parameters. Formation of ridges from smaller furrows can be realized with known soil cultivating means with difficulty only and at high costs. It is wearisome to control weeds on the sides of the ridge, loosening the earth, covering remnants of plant stems with earth and mixing with earth.
It is an unsolved problem to prepare "properly sedimented soil conditions" prior to sowing.